This invention relates to a bearing with improved lubrication seals and supporting a shaft element, the bearing being a tapered roller bearing which causes flow of lubricating oil supplied to the inside of a bearing in only one direction, and is able to prevent the penetration of foreign matter contained in the lubricating oil to the bearing.
Conventional tapered roller bearings used in the differential pinion shaft of an automobile are open bearings not provided with a seal, and lubricating oil inside the gear case is supplied to and lubricates the tapered roller bearing. However, the lubricating oil inside the gear case contains large quantities of iron filings and other foreign matter produced by contact and friction between the gears, said foreign matter penetrates the tapered roller bearing, and causes wear and damage to the bearings. Furthermore, because the bearing used in the differential pinion shaft is above the surface of the lubricating oil, when the viscosity of the oil is high as in cold regions or during sudden starts, seizing occurs or the bearing may be damaged because the lubricating oil reaches the bearing more than ten seconds after the shaft starts turning.
Thus, a shaft support device using a tapered roller bearing such as shown in FIG. 3 has been proposed (Japanese Patent Application Laid-Open No. 53-109049). This bearing support device is comprised of a gear case (housing) 1 which is filled with lubricating oil, a pinion shaft 5, and tapered roller bearing 6. Said tapered roller bearing 6 is sealed with seals 4 affixed to the inner race, and the inside of the bearing is filled with, for example, grease. Therefore, it is difficult for lubricating oil in gear case 1 to enter tapered roller bearing 6 filled with grease and sealed with the seals 4, and the bearing is not damaged by foreign matter in gear case 1. Furthermore, because the bearing is packed with grease, the bearing is not damaged in cold regions or in the case of sudden starts.
Nevertheless, the problem of bearing seizure and damage remains with the tapered roller bearing in the case in which the packed grease degrades and the bearing is not supplied with lubricant because the inside of the bearing sealed with seal 4 is packed with, for example, grease.